Method for operating a setting device for recording a driving request, setting device

Abstract

The invention relates to a method for operating an adjustment device (10) for detecting a driving request for a motor vehicle (1), comprising an actuating element (2) that can be operated by a driver of the motor vehicle (1), wherein the actuating element (2) is assigned at least one sensor (7) for detecting an actuation acting on the actuating element (2), and wherein the actuating element (2) is assigned at least one controllable actuator (9) for generating haptic feedback to the driver. It is provided that, in order to carry out a functional test of the adjustment device (10), the actuator (9) is controlled to generate haptic feedback, that a sensor signal from the sensor (7) is monitored in response to the haptic feedback, and that the functionality of the adjustment device (10) is determined depending on the sensor signal (7).

Description

[0001] The present invention relates to a method for operating an adjustment device for detecting a driving request for a motor vehicle, having an actuating element that can be actuated by a driver of the motor vehicle, wherein the actuating element is assigned at least one sensor for detecting an actuation acting on the actuating element, and wherein the actuating element is assigned at least one controllable actuator for generating haptic feedback to the driver.

[0002] Furthermore, the invention relates to an adjustment device for detecting a driving request for a motor vehicle, comprising an actuating element that can be actuated by a driver of the motor vehicle, wherein the actuating element is assigned at least one sensor for detecting an actuation acting on the actuating element, and wherein the actuating element is assigned at least one controllable actuator for generating haptic feedback to the driver. State of the art

[0003] Conventional motor vehicles have a hydraulic braking system that includes a brake pedal, which can be operated by a driver, as the actuating element, and a master cylinder mechanically coupled to the brake pedal. Pressing the brake pedal activates the master cylinder, or a hydraulic piston in the master cylinder is displaced by the brake pedal, generating hydraulic pressure in the master cylinder and distributing it to one or more brake circuits of the braking system. The hydraulic pressure buildup is thus at least partially achieved directly by pressing the brake pedal. In more modern motor vehicles, this pressure buildup is supported by a brake booster.

[0004] In newer motor vehicles, particularly in the context of increasing electrification, plans are being made to dispense with the mechanical connection between the actuating element and the actuator, especially the master brake cylinder. So-called brake-by-wire braking systems detect the actuation request or the driver's input using a sensor assigned to the actuating element and, depending on the sensor signal, control one or more actuators to fulfill the driving requirement. A corresponding braking system is known, for example, from published patent application EP 1 459 928 A2.

[0005] It is also known to associate a controllable actuator with the actuating element, which can provide the driver with haptic feedback when the actuating element is actuated. For example, it is known to alert the driver to certain events, such as the activation of ABS braking control, through a tactile impulse exerted on the actuating element by the actuator. Disclosure of the invention

[0006] The method according to the invention with the features of claim 1 has the advantage that the functionality of the adjustment device can be determined without additional hardware in order to increase the reliability of the braking system. If a functional error is detected, the driver can, for example, be made aware of it promptly. According to the invention, this is achieved in that, in order to carry out a functional test of the adjustment device, the actuator is controlled to generate haptic feedback, and a sensor signal from the sensor is monitored in response to the haptic feedback, and the functionality of the adjustment device is determined depending on the sensor signal. The invention therefore provides that one or more pulses are exerted on the actuating element by means of the actuator, which is already present, and that the actuating element is monitored for the occurrence of the feedback, in particular the pulse.If, for example, no pulse is detected by the sensor or sensor signal despite the actuator being activated, it is determined that the adjustment device is faulty or malfunctioning. Accordingly, a warning message is preferably issued to the driver, particularly along with a notice that a workshop must be visited and the braking system, or at least the adjustment device, must be checked or serviced. Optionally, the vehicle can be switched to a safe emergency driving mode. If the sensor detects the haptic feedback from the actuating element or a sensor signal that corresponds to the expected haptic feedback, the functionality of the adjustment device is preferably determined, and continued operation of the vehicle is authorized.

[0007] Preferably, the functional test is performed at regular intervals and / or after each commissioning of the adjustment device and / or a motor vehicle equipped with the adjustment device. This preferably ensures that the function of the control device is checked regularly and that driving can begin safely. Preferably, the functional test is performed after the motor vehicle has been unlocked, even before it is put into operation.

[0008] Preferably, the actuator is controlled to generate a vibration acting on the actuating element as haptic feedback. The vibration imposes a multitude of force pulses on the actuating element, which, if functioning correctly, result in an expected sensor signal. For example, the vibration is predetermined by its frequency and amplitude. Preferably, the actual vibration of the actuating element detected by the sensor is compared with the specified vibration to determine the functionality of the adjustment device.

[0009] Particularly preferably, the vibration is generated with a predetermined vibration profile. For example, the vibration may have a constant amplitude and frequency. Alternatively, a vibration profile is predetermined whose amplitude and / or frequency varies at least once over the duration of the haptic feedback or vibration.

[0010] Preferably, the detected sensor signal is compared with a sensor signal dependent on the predetermined vibration profile or expected, and the functionality of the adjustment device is determined if the detected sensor signal corresponds to or nearly corresponds to the expected transmission signal. This results in the advantages already mentioned above.

[0011] Preferably, a warning message is issued to the driver of the motor vehicle if the detected sensor signal does not match the expected sensor signal or does not match it closely. Optionally, the motor vehicle is switched to emergency mode. This can be done, for example, by preventing the motor vehicle from being started after a malfunction has been detected during the functional test.

[0012] Particularly preferably, the sensor monitors an actuation force and / or an actuation travel of the actuation element as an actuation. Both the actuation force and the actuation travel reflect a haptic feedback, in particular a force impulse, exerted by the actuator on the actuation element. Thus, by detecting or monitoring the actuation force and / or actuation travel, the haptic feedback applied or generated by the sensor can be reliably determined when the sensor and / or the adjustment device are functioning correctly.

[0013] The adjustment device according to the invention with the features of claim 8 is characterized by a control unit that is specifically designed to carry out the method according to the invention when used as intended. This results in the advantages already mentioned above.

[0014] Preferably, the actuating element is designed to be deformable, at least in certain regions. The actuating element can be mounted fixedly or movably in the motor vehicle. Due to the deformability of the actuating element, regardless of the type of mounting, an actuating force and / or an actuating travel (in the area of ​​deformation) of the actuating element can be detected by the at least one sensor and used to test the function of the adjustment device.

[0015] Furthermore, it is preferably provided that the actuating element is held displaceably on a bearing device. The bearing device is designed to be fastened in the motor vehicle, in particular in the footwell of the motor vehicle, so that a displacement of the actuating element can advantageously be detected or monitored by the sensor. Alternatively, the actuating element is held fixedly or immovably by the bearing device, in which case the actuating element is preferably designed to be elastically deformable in certain regions, as already described above.

[0016] Particularly preferably, the sensor is designed to detect an actuating force and / or an actuating travel. For this purpose, the sensor is designed, for example, as a force sensor or a travel sensor. This results in the advantages already mentioned above.

[0017] Further advantages and preferred features and combinations of features emerge in particular from the above description and from the claims. The invention will be explained in more detail below with reference to the drawings. Fig. 1 a motor vehicle with an advantageous setting device for detecting a driving request, Fig. 2 a flow chart to explain an advantageous method for operating the setting device and Fig. 3 a diagram to further explain the procedure.

[0018] Fig. Figure 1 shows a simplified representation of the footwell of a motor vehicle 1 (not shown in detail here), in which an actuating element 2 of a braking system 3 is arranged. The actuating element 2 is a brake pedal in the present case, or alternatively an accelerator pedal, which the driver of the motor vehicle 1 can actuate with his foot. The brake pedal 2 is held displaceably on a bearing device 4, which is fastened in the footwell, in particular in such a way that it can be pivoted about a pivot axis 5 by the driver, as indicated by an arrow 6 in Fig. 1 is displayed.

[0019] A sensor 7 is assigned to the actuating element 2, by means of which an actuating force acting on the actuating element 2 and / or an actuating travel set by the actuation of the actuating element 2 according to arrow 6 of the actuating element 2 can be detected. Thus, actuation of the brake pedal or the actuating lever 2 can be monitored by means of the sensor 7.

[0020] Sensor 7 is connected, at least in terms of signaling, to a control unit 8, which monitors and evaluates the transmitted signal of sensor 7 in order to determine a driver request, in particular a braking torque request, depending on a detected actuating force and / or a detected actuating travel. And to control at least one actuator of a braking system of motor vehicle 1 to adjust a braking force depending on the determined braking request.

[0021] Furthermore, a controllable actuator 9 is assigned to the actuating element 2. This actuator 9 is also connected to the control unit 8, at least for signaling purposes, and is designed to exert haptic feedback on the actuating element 2. The actuator 9 can be controlled, for example, to exert a force pulse on the actuating element 2 that can be detected by the driver. The control unit 8 is designed, in particular, to control the actuator 9 to generate a single force pulse or multiple force pulses in the form of a vibration that act on the actuating element 2.

[0022] At least the actuating element 2 and the sensor 7 together form an advantageous adjustment device 10 for detecting a driver's request, in the present case a braking request from the driver.

[0023] With reference to Fig. 2, an advantageous method for operating the adjustment device 10 will be described below. Fig. Figure 2 shows a simplified flow chart in which several process steps are shown.

[0024] In a first step S1, the setting device 10 is activated. This occurs, in particular, promptly after a detected unlocking of the motor vehicle 1.

[0025] In a subsequent step S2, a functional test of the adjustment device 10 is initiated. For this purpose, the control unit 8 controls the actuator 9 to exert a predetermined haptic feedback on the actuating element 2 in the form of one or more force pulses.

[0026] In the subsequent step S3, the sensor signal of sensor 7 is monitored or examined to determine whether the force pulse(s) generated by actuator 9 were or are detected by sensor 7. For this purpose, sensor signal 7 is compared with a sensor signal expected based on the predetermined haptic feedback. This comparison is performed in a subsequent step S4.

[0027] Fig.3 shows two characteristic curves K1 and K2 in a diagram plotted over time t, wherein characteristic curve K1 shows an expected sensor signal and characteristic curve K2 shows the actual sensor signal of sensor 7 as a result of the control of actuator 9. Preferably, actuator 9 is controlled to generate a predetermined vibration characterized by the amplitude and frequency of force pulses. According to the present exemplary embodiment, the vibration has five force pulses I1 to I5. While the frequencies of the pulses are constant according to the present exemplary embodiment, their amplitude changes to a lower amplitude after the third pulse I3. The vibration thus has a predetermined vibration pattern. Based on characteristic curve K2, which represents the sensor signal of sensor 7, it can be seen that the detected pulses correspond to the generated or desired pulses of actuator 9.For simplicity, the detected pulses are shown slightly offset from the generated pulses. In reality, depending on the hardware used, a time offset is no longer or barely noticeable. In this case, it can be determined that the detected signal corresponds to the expected signal or the generated pulses (j). Thus, the query in step S4 determines that the adjustment device 10 is functional. The method is thus terminated or repeated with step S1 or step S2 at regular intervals.

[0028] However, if the detected sensor signal deviates from the expected sensor signal, for example because different amplitudes are detectable or no pulses are detected (n), a warning message is issued to the driver of the motor vehicle in a subsequent step S5, in particular with the indication that a workshop must be visited promptly because the adjustment device 10 is no longer functioning properly.

[0029] Actuator 9 generates an acceleration acting on actuating element 2, which causes a pedal force. The vibration occurs with the predetermined vibration profile, for which the sensor response is known in the form of the expected sensor signal. The expected sensor signal is recorded and stored, for example, in advance in tests or in pre-prepared steps using a known-functioning adjustment device. For example, the vibration generates a sensor signal of 5 N, which is detected by control unit 8.

[0030] Preferably, sensor 7 is configured with multiple channels, so that when sensor 7 is functioning, the expected sensor signal is detected in all channels. If a sensor channel fails, the pulse can no longer be detected in the sensor channel, and it can be concluded that this channel, and thus sensor 7, is faulty. The motor vehicle can continue to operate using the remaining channels; nevertheless, a warning message is preferably issued to the driver according to step S5.

[0031] Instead of a sensor with multiple channels, several sensors 7 can be used to monitor the actuation of the brake pedal in order to mutually verify the sensor signals.

[0032] For example, if it is known that the vibration or force pulse is intended to generate a sensor value of 5N, a threshold is optionally defined above which a malfunction is assumed if the threshold is not reached.

[0033] This functional test is preferably performed when the adjustment device 10 has not yet been activated by the driver, i.e., shortly after the motor vehicle 1 has been operated, in particular after the motor vehicle has been unlocked and / or a driver's door has been opened. Thus, the opening of the driver's door and / or the unlocking of the motor vehicle 1 is preferably monitored, and as soon as an opening or unlocking is detected, the functional test described above is initiated in step S1.

[0034] In this respect, the sensor 7 is preferably a force sensor or a displacement sensor. Both a force sensor and a displacement sensor can also be assigned to the actuating element 2 in order to monitor its actuation and verify the plausibility of the actuation. QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] EP 1 459 928 A2

[0004]

Claims

[1] Method for operating an adjustment device (10) for detecting a driving request for a motor vehicle (1), with an actuating element (2) that can be actuated by a driver of the motor vehicle (1), wherein the actuating element (2) is assigned at least one sensor (7) for detecting an actuation acting on the actuating element (2), wherein the actuating element (2) is assigned at least one controllable actuator (9) for generating a haptic feedback to the driver, characterized by in that, in order to carry out a functional test of the adjustment device (10), the actuator (9) is controlled to generate a haptic feedback, that a sensor signal of the sensor (7) is monitored in response to the haptic feedback, and that the functionality of the adjustment device (10) is determined as a function of the sensor signal (7). [2] Method according to claim 1, characterized bythat the functional test is carried out at regular intervals and / or after each commissioning of the adjustment device (10) and / or of a motor vehicle having the adjustment device (10). [3] Method according to one of the preceding claims, characterized by that the actuator (9) is controlled to generate a vibration acting on the actuating element (2) as haptic feedback. [4] Method according to one of the preceding claims, characterized by that the vibration is generated with a predetermined vibration profile. [5] Method according to one of the preceding claims, characterized by that the detected sensor signal (7) is compared with an expected sensor signal dependent on the predetermined vibration profile, and that the functionality of the adjusting device (10) is determined when the detected sensor signal (7) corresponds or almost corresponds to the expected sensor signal. [6] Method according to one of the preceding claims, characterized by that a warning message is issued if the detected sensor signal (7) does not correspond or does not nearly correspond to the expected sensor signal. [7] Method according to one of the preceding claims, characterized by that an actuating force and / or an actuating path of the actuating element (2) are monitored by the sensor (7) as an actuation. [8] Adjustment device (10) for detecting a driving request for a motor vehicle (1), with an actuating element (2) that can be actuated by a driver of the motor vehicle (1), wherein the actuating element (2) is assigned at least one sensor (7) for detecting an actuation acting on the actuating element (2), and wherein the actuating element (2) is assigned at least one controllable actuator (9) for generating a haptic feedback to the driver, characterized bya control device (8) which is specially designed to carry out a method according to one of claims 1 to 7 when used as intended. [9] Adjustment device according to claim 8, characterized by that the actuating element (2) is designed to be elastically deformable at least in some regions. [10] Adjustment device according to one of claims 8 or 9, characterized by that the actuating element (2) is held displaceably on a bearing device (4). [11] Adjustment device according to one of claims 8 to 10, characterized by that the actuating element (2) is designed as a foot pedal or as a handle. [12] Adjustment device according to one of claims 8 to 11, characterized by that the sensor (7) is designed to detect an actuating force or an actuating movement.

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